They're accused of paying the president of Chad and the Ugandan foreign minister at the time to secure business advantages for the Chinese firm.

"Wiring almost a million dollars through New York's banking system in furtherance of their corrupt schemes, the defendants allegedly sought to generate business through bribes paid to the president of Chad and the Ugandan foreign minister," the statement quoted the acting US attorney for the Southern District of New York as saying.

The defendants stand accused of wiring almost a million dollars through New York's banking system as part of "an international corruption scheme that spanned the globe".

Acting Assistant Attorney General Kenneth Blanco said the scheme involved bribes at the "highest levels of the governments" of two nations.

The justice department alleged that Mr Ho set up both bribery schemes and enlisted the assistance of Mr Gadio, who it said "had a personal relationship with the President of Chad".

There has been no official comment from authorities in Chad and Uganda so far.

The Chinese oil and gas company was not identified in the announcement by the US justice department, but described as a "Shanghai-headquartered multi-billion dollar conglomerate that operates internationally in the energy and financial sectors".

The two men were officially charged with violating the Foreign Corrupt Practices Act (FCPA) and international money laundering.

Under that legislation, it is illegal to bribe foreign officials to gain a business advantage.